/*

 * Licensed to the Apache Software Foundation (ASF) under one

 * or more contributor license agreements.  See the NOTICE file

 * distributed with this work for additional information

 * regarding copyright ownership.  The ASF licenses this file

 * to you under the Apache License, Version 2.0 (the

 * "License"); you may not use this file except in compliance

 * with the License.  You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

package com.bff.gaia.unified.sdk.extensions.sql.impl.rule;



import com.bff.gaia.unified.sdk.extensions.sql.impl.rel.UnifiedLogicalConvention;

import com.bff.gaia.unified.sdk.extensions.sql.impl.rel.UnifiedUnionRel;

import org.apache.calcite.plan.Convention;

import org.apache.calcite.rel.RelNode;

import org.apache.calcite.rel.convert.ConverterRule;

import org.apache.calcite.rel.core.Union;

import org.apache.calcite.rel.logical.LogicalUnion;



/**

 * A {@code ConverterRule} to replace {@link org.apache.calcite.rel.core.Union} with {@link

 * UnifiedUnionRule}.

 */

public class UnifiedUnionRule extends ConverterRule {

  public static final UnifiedUnionRule INSTANCE = new UnifiedUnionRule();



  private UnifiedUnionRule() {

    super(LogicalUnion.class, Convention.NONE, UnifiedLogicalConvention.INSTANCE, "UnifiedUnionRule");

  }



  @Override

  public RelNode convert(RelNode rel) {

    Union union = (Union) rel;



    return new UnifiedUnionRel(

        union.getCluster(),

        union.getTraitSet().replace(UnifiedLogicalConvention.INSTANCE),

        convertList(union.getInputs(), UnifiedLogicalConvention.INSTANCE),

        union.all);

  }

}